1. Field of the Invention
The invention relates to substituted 1,1,2-triphenylbutenes which are structurally related to tamoxifen, a drug used in the treatment of oestrogen-dependent cancer, especially breast cancer, and their use for the same purpose.
2. Background of the Inventions
Researchers into anti-cancer drugs continually seek to improve on existing drugs, in particular to increase their efficacy. Many variations of the structure of tamoxifen have already been proposed. One such proposal is contained in our U.S. Pat. 4,839,155. (The European counterpart is EP-B 260 066). This patent claims 3- and 4-iodotamoxifen derivatives of formula (1): ##STR2## wherein I represents a 3- or 4-iodo substituent and R.sup.1 and R.sup.2, which may be the same or different, represent C.sub.1-3 alkyl groups or R.sup.1 represents a hydrogen atom and R.sup.2 a C.sub.1-3 alkyl group and R.sup.1 and R.sup.2 together with the nitrogen atom to which they are attached represent a saturated heterocyclic group, in the form of the free bases or their pharmaceutically acceptable acid addition salts. Preferably R.sup.1 and R.sup.2 represent methyl groups or R.sup.1 and R.sup.2 together with the said nitrogen atom, represent a pyrrolidino group. The most preferred such compounds have the iodine atom in the 4-position of the phenyl group and are termed "4-iodo tamoxifen" and "Idoxlfene" respectively.